US3920367A - Mold pressure control apparatus - Google Patents

Mold pressure control apparatus Download PDF

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Publication number
US3920367A
US3920367A US358839A US35883973A US3920367A US 3920367 A US3920367 A US 3920367A US 358839 A US358839 A US 358839A US 35883973 A US35883973 A US 35883973A US 3920367 A US3920367 A US 3920367A
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US
United States
Prior art keywords
pressure
signal
mold
cycle
cavity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US358839A
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English (en)
Inventor
Carlton Y W Ma
Edwin Dean Ailman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Milacron Inc
Original Assignee
Milacron Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Milacron Inc filed Critical Milacron Inc
Priority to US358839A priority Critical patent/US3920367A/en
Priority to AU64515/74A priority patent/AU6451574A/en
Priority to NL7400513A priority patent/NL7400513A/xx
Priority to DE2402798A priority patent/DE2402798A1/de
Priority to BE140106A priority patent/BE810076A/xx
Priority to CH96274A priority patent/CH563863A5/xx
Priority to AT66974*#A priority patent/AT328719B/de
Priority to FR7403939A priority patent/FR2228600B3/fr
Priority to IT67389/74A priority patent/IT1004925B/it
Priority to JP49030693A priority patent/JPS503466A/ja
Priority to BR2530/74A priority patent/BR7402530D0/pt
Priority to CA199,139A priority patent/CA1001264A/en
Priority to GB2048474A priority patent/GB1449728A/en
Priority to ES426188A priority patent/ES426188A1/es
Priority to ZA00743006A priority patent/ZA743006B/xx
Application granted granted Critical
Publication of US3920367A publication Critical patent/US3920367A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/76—Measuring, controlling or regulating
    • B29C45/77—Measuring, controlling or regulating of velocity or pressure of moulding material

Definitions

  • the pressure in the mold cavity during the holding phase is converted into an electrical quantity which is then integrated over a predetermined timeinterval and compared with a reference signal to provide an error signal.
  • This signal is used to modify the holding phase and therefore provides a means for obtaining consistent results insofar as part size and quality ,is concemed.
  • FIG. 1 is a schematic diagram of a preferred embodiment of the invention.
  • FIG. 2 is a graph showing a set of typical pressure time curves, one denoting pressure in the nozzle and the other denoting pressure in the mold.
  • FIG. l I DESCRIPTION OF PREFERRED EMBODIMENT
  • the present invention is shown incorporated in the injection molding apparatus illustrated schematically in FIG. l wherein a barrel housing a screw or ram 11 receives molding compound from a hopper l2. Rota- ,tion of the screw by a motor 13 causes the molding compound to be fed to the forward end of the barrel where it accumulates in front of the screw as the latter is forced rearwardly against back pressure provided by a cylinder 14.
  • the cylinder contains a piston 15 mounted on the rear end of the screw 11 and is supplied with hydraulic pressure from a source 16 through a line 17.
  • the barrel terminates in a nozzle 20 which fits into the sprue or gate of a mold 21 having a cavity 22 formed therein.
  • This portion of the cycle is represented by the left hand part of the curve 23 (FIG. 2) which indicates the build-up in pressure ahead of the screw when it moves forwardly in the barrel.
  • the pressure in the mold cavity, represented by the lower curve 24, remains approximately zero until the cavity is filled after which it rises to a maximum where it is held by the holding pressure applied by the screw until the gate freezes.
  • the switch from injection pressure to a somewhat lower holding pressure is affected by a position readout mechanism 25 which applies a signal to a switching control 26 where it is compared with a reference position signal 27.
  • a gating signal is transmitted to a valve driver circuit 28 which is thereby enabled and causes a modulating signal to be applied to a pressure control valve 30.
  • a signal is sent to a cycle controller 29 which energizes the solenoid of a valve 31 which connects the pressure control valve 30 to the line 17 so as to maintain holding pressure on the screw.
  • the pressure in the mold cavity is sensed by a transducer 32 and the low-level signal therefrom is amplified at 33 and thence delivered to an integrating circuit 34.
  • the output of amplifier 33 is also passed to a circuit 35 where it is compared with a reference signal derived from a source 36.
  • the output of the circuit 35' is transmitted to a timer 37 and gates the timer on whenever the output is positive.
  • the reference signal is set to correspond to a low pressure in the mold, say psi, and so prevents operation of the timer 37 if any blockage occurs in the nozzle or the sprue which prevents pressure build-up in the mold.
  • a reset signal is transmitted from the timer to the integrator 34 to set it to zero.
  • the timer transmits a signal to the integrator to initiate summation of the mold pressure. This time is indicated at 1 in FIG. 2.
  • the timer transmits a further signal to theintegrator to stop the integration process. The time when this occurs is indicated at t in FIG. 2.
  • the signal representing the integral of the mold pressure from t, to t is transmitted to a circuit 40 where it is compared with a mold pressure reference signal obtained from a source 41 which may be manually adjusted to the desired holding pressure within the mold cavity.
  • the difference or error signal is introduced into a sample and memory circuit 42 which is reset prior to storing the error signal for use during the next cycle of operation of the molding machine.
  • the error signal is read out of the memory 42 and passed through a gain control circuit 43 where its scale is adjusted to correspond to 3 that of the injection pressure.
  • the adjusted error signal is introduced into a summing circuit 44 where it is combined with an injection pressure reference signal derived from a sample and memory circuit 45.
  • This memory is loaded from an injection pressure reference source 46 prior to or during the first cycle of the machine.
  • the reference signal is retained in the memory 45 and updated from cycle to cycle with the mold pressure error signal.
  • the injection pressure signal is applied to pressure control valve driver 28 where its power is increased sufficiently to enable it, when gated, to operate the torque motor of valve 30.
  • the output of the summing circuit 44 is also transmitted to a buffer store 47 where it is held until the end of the cycle whereupon it is used to update the memory 45 in readiness for the next cycle when it will again be modified by the mold pressure error signal, if any, and applied to the control valve 30 via the driver 28.
  • modulating means includes a memory unit for storing a holding pressure reference signal from one cycle to the next, and means for updating the holding pressure reference signal with the error signal pro: prised in the preceding cycle so as to provide the correct holding pressure in the current cycle.
  • the mold pressure control means of claim 2 in which said modulating means also includes an electrically modulated pressure control valve, and means for driving said valve with the updated holding pressure reference signalv 4.
  • said timing means includes a timer for initiating and terminating integration of the cavity pressure signal by said integrating circuit, and means for activating said timer when the mold cavity pressure exceeds a predetermined value, said activating means including a reference signal source and a comparator for comparing the cavity pressure signal with the reference signal from said source.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
US358839A 1973-05-10 1973-05-10 Mold pressure control apparatus Expired - Lifetime US3920367A (en)

Priority Applications (15)

Application Number Priority Date Filing Date Title
US358839A US3920367A (en) 1973-05-10 1973-05-10 Mold pressure control apparatus
AU64515/74A AU6451574A (en) 1973-05-10 1974-01-15 Mold pressure control apparatus
NL7400513A NL7400513A (de) 1973-05-10 1974-01-15
DE2402798A DE2402798A1 (de) 1973-05-10 1974-01-22 Steuergeraet zur steuerung des druckes in der giessform einer spritzgiessmaschine
BE140106A BE810076A (fr) 1973-05-10 1974-01-23 Appareil de commande de pression de moule
CH96274A CH563863A5 (de) 1973-05-10 1974-01-24
AT66974*#A AT328719B (de) 1973-05-10 1974-01-28 Steuergerat fur den druck in der giessform einer spritzgiessmaschine
FR7403939A FR2228600B3 (de) 1973-05-10 1974-02-06
IT67389/74A IT1004925B (it) 1973-05-10 1974-02-12 Dispositivo regolatore della pressione di stampaggio nelle presse ad iniezione
JP49030693A JPS503466A (de) 1973-05-10 1974-03-19
BR2530/74A BR7402530D0 (pt) 1973-05-10 1974-03-29 Dispositivo de controle de pressao de molde e maquina de moldagem por injecao controlada automaticamente
CA199,139A CA1001264A (en) 1973-05-10 1974-05-07 Mold pressure control apparatus
GB2048474A GB1449728A (en) 1973-05-10 1974-05-09 Injection moulding
ES426188A ES426188A1 (es) 1973-05-10 1974-05-10 Perfeccionamientos en aparatos para el control de la presi-on del molde de maquinas de moldeo por inyeccion.
ZA00743006A ZA743006B (en) 1973-05-10 1974-05-10 Mold pressure control apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US358839A US3920367A (en) 1973-05-10 1973-05-10 Mold pressure control apparatus

Publications (1)

Publication Number Publication Date
US3920367A true US3920367A (en) 1975-11-18

Family

ID=23411256

Family Applications (1)

Application Number Title Priority Date Filing Date
US358839A Expired - Lifetime US3920367A (en) 1973-05-10 1973-05-10 Mold pressure control apparatus

Country Status (15)

Country Link
US (1) US3920367A (de)
JP (1) JPS503466A (de)
AT (1) AT328719B (de)
AU (1) AU6451574A (de)
BE (1) BE810076A (de)
BR (1) BR7402530D0 (de)
CA (1) CA1001264A (de)
CH (1) CH563863A5 (de)
DE (1) DE2402798A1 (de)
ES (1) ES426188A1 (de)
FR (1) FR2228600B3 (de)
GB (1) GB1449728A (de)
IT (1) IT1004925B (de)
NL (1) NL7400513A (de)
ZA (1) ZA743006B (de)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982865A (en) * 1974-03-21 1976-09-28 Hoffmann-La Roche Inc. Apparatus for high-speed accurate counting and handling of discrete objects such as tablets
US4047558A (en) * 1974-06-28 1977-09-13 Honsel Werke Aktiengesellschaft Metering device for metal casting machines, particularly low pressure casting machines
US4060362A (en) * 1975-05-12 1977-11-29 International Business Machines Corporation Injection molding same cycle control
US4100598A (en) * 1975-09-05 1978-07-11 Hoffmann-La Roche Inc. Tablet press related instrumentation for use in development and control of formulations of pharmaceutical granulations
US4222725A (en) * 1978-02-27 1980-09-16 Solid Controls, Inc. Electro-hydraulic ram control apparatus
US4326255A (en) * 1978-04-13 1982-04-20 Toshiba Kikai Kabushiki Kaisha Apparatus for controlling plasticizing process of in-line screw-type injection molding machine
US4387064A (en) * 1981-08-03 1983-06-07 Werderitch Frank J Method and apparatus for sorting defective parts
US4411609A (en) * 1980-04-18 1983-10-25 Hitachi, Ltd. Apparatus for molding plastic
US4510103A (en) * 1982-09-28 1985-04-09 Agency Of Industrial Science And Technology Method of molding a composite body involving a thermosetting resin
US4563744A (en) * 1982-02-23 1986-01-07 Toshiba Kikai Kabushiki Kaisha Apparatus for adjusting starting positions of high speed injection
US4675141A (en) * 1983-10-24 1987-06-23 Toshiba Kikai Kabushiki Kaisha Method of controlling pressurized gas, before and after injecting a molten material, in a mold cavity
US4735760A (en) * 1985-01-24 1988-04-05 Toshiba Kikai Kabushiki Kaisha Method and apparatus for controlling injection step of injection molding machines
US4798527A (en) * 1988-03-07 1989-01-17 Vickers, Incorporated Control system for injection molding machine
US4832883A (en) * 1985-12-17 1989-05-23 The Japan Steel Works, Ltd. Method and apparatus for controlling screw positions in injection molding machine
US4968462A (en) * 1987-01-30 1990-11-06 Sumitomo Heavy Industries, Ltd. Method and apparatus for setting injection pressure of injection molding machine
WO1992013301A1 (en) * 1991-01-18 1992-08-06 Cincinnati Milacron Inc. Control for injection molding machine
CN102773982A (zh) * 2011-05-09 2012-11-14 发那科株式会社 具有树脂材料的夹入防止功能的注塑成型机
CN109249567A (zh) * 2018-10-25 2019-01-22 遂宁市金虹机械厂 一种滴塑机卸模控制系统及方法
US11020889B2 (en) 2013-09-05 2021-06-01 Husky Injection Molding Systems Ltd. Method and system for generating, processing and displaying an indicator of performance of an injection molding machine
US11186021B2 (en) * 2015-12-09 2021-11-30 Synventive Molding Solutions, Inc. Adjusted cavity injection fluid pressures in injection molding system

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5186566A (ja) * 1975-01-29 1976-07-29 Hitachi Ltd Shashitsuseikeikinoshashitsuatsuryokuseigyohoho
DE2514009C3 (de) * 1975-03-29 1981-03-12 Robert Bosch Gmbh, 7000 Stuttgart Kunststoff-Spritzgießmaschine mit einer Regelvorrichtung zum Regeln des auf eine Plastifizier- und Einspritzschnecke einwirkenden Hydraulikdruckes
JPS5638237A (en) * 1979-09-07 1981-04-13 Hitachi Ltd Adaptive control method for multiple clamp-mold injection molding machine
JPS5774136A (en) * 1980-10-28 1982-05-10 Toyo Kikai Kinzoku Kk Automatic mold clamping method for toggle type clamping device
DE3204756A1 (de) * 1982-02-11 1983-08-18 Peter Prof. Dipl.-Ing. 7080 Aalen Wippenbeck Verfahren zum fuellen eines formwerkzeugs mit plastifizierbarem material mittels eines einspritzkolbens oder einer als einspritzkolben wirkenden schubschnecke sowie vorrichtung zur durchfuehrung des verfahrens
JPS625827A (ja) * 1985-07-03 1987-01-12 Fuji Electric Co Ltd 射出成形機の制御方法
EP0228799A3 (de) * 1985-11-18 1988-08-03 The Japan Steel Works, Ltd. Verfahren zum Steuern eines Spritzgiessvorgangs und Vorrichtung dazu
DE3738248A1 (de) * 1987-11-11 1988-04-28 Ver Foerderung Inst Kunststoff Verfahren zur reproduzierbaren werkzeugfuellung mit reagierenden formmassen
JPH0655383B2 (ja) * 1990-03-19 1994-07-27 住友電装株式会社 射出成形機における成形評価装置および成形評価方法
AU641245B2 (en) * 1990-03-28 1993-09-16 Moldflow Pty Ltd Control of injection moulding machine
US5578256A (en) * 1990-03-28 1996-11-26 Moldflow Pty, Ltd Control of injection moulding machine
US5151282A (en) * 1991-05-13 1992-09-29 Dray Robert F Positive-type non-return valve
US5766526B1 (en) * 1994-04-20 1999-08-24 Fuji Photo Film Co Ltd Method and apparatus for injection molding

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521046A (en) * 1968-02-06 1970-07-21 Lear Siegler Inc Analog computer circuit for multiplication or division
US3642404A (en) * 1968-11-21 1972-02-15 Meiki Seisakusho Kk Injection-molding machine
US3721512A (en) * 1970-10-22 1973-03-20 Cincinnati Milacron Inc Plastication control system for injection molding machines
US3767339A (en) * 1971-11-01 1973-10-23 Hunkar Instr Dev Labor Inc Injection molding control
US3799719A (en) * 1969-08-25 1974-03-26 British Insulated Callenders Apparatus for extruding plastic material

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521046A (en) * 1968-02-06 1970-07-21 Lear Siegler Inc Analog computer circuit for multiplication or division
US3642404A (en) * 1968-11-21 1972-02-15 Meiki Seisakusho Kk Injection-molding machine
US3799719A (en) * 1969-08-25 1974-03-26 British Insulated Callenders Apparatus for extruding plastic material
US3721512A (en) * 1970-10-22 1973-03-20 Cincinnati Milacron Inc Plastication control system for injection molding machines
US3767339A (en) * 1971-11-01 1973-10-23 Hunkar Instr Dev Labor Inc Injection molding control

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3982865A (en) * 1974-03-21 1976-09-28 Hoffmann-La Roche Inc. Apparatus for high-speed accurate counting and handling of discrete objects such as tablets
US4047558A (en) * 1974-06-28 1977-09-13 Honsel Werke Aktiengesellschaft Metering device for metal casting machines, particularly low pressure casting machines
US4060362A (en) * 1975-05-12 1977-11-29 International Business Machines Corporation Injection molding same cycle control
US4100598A (en) * 1975-09-05 1978-07-11 Hoffmann-La Roche Inc. Tablet press related instrumentation for use in development and control of formulations of pharmaceutical granulations
US4222725A (en) * 1978-02-27 1980-09-16 Solid Controls, Inc. Electro-hydraulic ram control apparatus
US4326255A (en) * 1978-04-13 1982-04-20 Toshiba Kikai Kabushiki Kaisha Apparatus for controlling plasticizing process of in-line screw-type injection molding machine
US4411609A (en) * 1980-04-18 1983-10-25 Hitachi, Ltd. Apparatus for molding plastic
US4387064A (en) * 1981-08-03 1983-06-07 Werderitch Frank J Method and apparatus for sorting defective parts
US4563744A (en) * 1982-02-23 1986-01-07 Toshiba Kikai Kabushiki Kaisha Apparatus for adjusting starting positions of high speed injection
US4510103A (en) * 1982-09-28 1985-04-09 Agency Of Industrial Science And Technology Method of molding a composite body involving a thermosetting resin
US4675141A (en) * 1983-10-24 1987-06-23 Toshiba Kikai Kabushiki Kaisha Method of controlling pressurized gas, before and after injecting a molten material, in a mold cavity
US4735760A (en) * 1985-01-24 1988-04-05 Toshiba Kikai Kabushiki Kaisha Method and apparatus for controlling injection step of injection molding machines
US4832883A (en) * 1985-12-17 1989-05-23 The Japan Steel Works, Ltd. Method and apparatus for controlling screw positions in injection molding machine
US4968462A (en) * 1987-01-30 1990-11-06 Sumitomo Heavy Industries, Ltd. Method and apparatus for setting injection pressure of injection molding machine
US4798527A (en) * 1988-03-07 1989-01-17 Vickers, Incorporated Control system for injection molding machine
WO1992013301A1 (en) * 1991-01-18 1992-08-06 Cincinnati Milacron Inc. Control for injection molding machine
US5229952A (en) * 1991-01-18 1993-07-20 Cincinnati Milacron Inc. Control for injection molding machine
CN102773982A (zh) * 2011-05-09 2012-11-14 发那科株式会社 具有树脂材料的夹入防止功能的注塑成型机
CN102773982B (zh) * 2011-05-09 2013-10-09 发那科株式会社 具有树脂材料的夹入防止功能的注塑成型机
US11020889B2 (en) 2013-09-05 2021-06-01 Husky Injection Molding Systems Ltd. Method and system for generating, processing and displaying an indicator of performance of an injection molding machine
US11186021B2 (en) * 2015-12-09 2021-11-30 Synventive Molding Solutions, Inc. Adjusted cavity injection fluid pressures in injection molding system
CN109249567A (zh) * 2018-10-25 2019-01-22 遂宁市金虹机械厂 一种滴塑机卸模控制系统及方法
CN109249567B (zh) * 2018-10-25 2023-06-23 遂宁市金虹机械厂 一种滴塑机卸模控制系统及方法

Also Published As

Publication number Publication date
AT328719B (de) 1976-04-12
CH563863A5 (de) 1975-07-15
NL7400513A (de) 1974-11-12
FR2228600B3 (de) 1976-11-26
ZA743006B (en) 1975-05-28
GB1449728A (en) 1976-09-15
IT1004925B (it) 1976-07-20
FR2228600A1 (de) 1974-12-06
DE2402798A1 (de) 1974-12-05
AU6451574A (en) 1975-07-17
JPS503466A (de) 1975-01-14
CA1001264A (en) 1976-12-07
BR7402530D0 (pt) 1974-12-03
ATA66974A (de) 1975-06-15
ES426188A1 (es) 1976-07-01
BE810076A (fr) 1974-05-16

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